iPXE Script Variables | NVIDIA Infra Controller

When a machine network-boots, NICo’s PXE service serves it an iPXE script. That script sets a small number of variables before running the boot instructions, so anything those instructions reference— including a custom ipxeScript supplied through the REST API or an operating-system definition—can use them instead of hard-coding a site’s URLs.

The variables are set by the PXE service, so they always carry the URLs that particular machine can reach. A machine on a segment that reaches NICo under a different name gets that name substituted automatically; a script that hard-codes a hostname instead does not.

Available Variables

Variable	Value	Use It For
`${base-url}`	The boot-artifact tree, `…/public/blobs/`	Chaining to a kernel, initrd, or EFI image NICo serves
`${tenant-cloudinit-url}`	The NoCloud datasource for an assigned instance	`ds=nocloud-net;s=${tenant-cloudinit-url}` in an OS install script
`${dpu-cloudinit-url}`	The BlueField kickstart endpoint	Internal—DPU provisioning only
`${scout-cloudinit-url}`	The discovery OS’s NoCloud datasource	Internal—set on the Scout kernel command line only
`${cloudinit-url}`	Alias of `${tenant-cloudinit-url}`	Deprecated—refer to Deprecations.

${dpu-cloudinit-url} and ${scout-cloudinit-url} are listed for completeness. They serve NICo’s own provisioning flows, and referencing them from a tenant script will not do anything useful.

Typical Use

The following example boots an OS installer with a cloud-init data source:

#!ipxe
kernel ${base-url}/internal/x86_64/vmlinuz ip=dhcp autoinstall ds=nocloud-net;s=${tenant-cloudinit-url} initrd=initrd.magic
initrd ${base-url}/internal/x86_64/initrd
boot

The ${tenant-cloudinit-url} data source serves the user-data, meta-data, vendor-data, and network-config documents that the cloud-init NoCloud data source expects. user-data contains the userData value from the machine’s operating system. If no value is set, NICo serves an empty document, and the boot continues.

Deprecations

${cloudinit-url} Variable

Deprecated in favor of ${tenant-cloudinit-url}. Update scripts that use it.

${cloudinit-url} is the original single cloud-init URL. Each consumer now has a separate prefix: tenant instances, DPUs being provisioned, and hosts running the discovery OS. The prefix identifies the consumer without requiring the service to infer it from ambiguous data.

${cloudinit-url} remains an alias for ${tenant-cloudinit-url} and continues to work unchanged, so existing scripts keep booting. This alias is deprecated. Scripts referencing it should move to ${tenant-cloudinit-url}; the substitution is the only change required.